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      <title>Netty发送消息的方式 - 交互式测验</title>
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          <div class="quiz-container">
            <div class="quiz-header">
              <h1>Netty发送消息的方式 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
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      <script>
        const quizData = [
  {
    "question": "在Netty发送消息的基本流程中，`write()`方法和`flush()`方法的核心区别是什么？",
    "options": [
      "`write()`是同步阻塞操作，而`flush()`是异步非阻塞操作。",
      "`write()`将消息放入内部缓冲区（发送队列），而`flush()`将缓冲区中的消息实际发送到网络中。",
      "`write()`负责对消息进行业务逻辑处理，`flush()`负责将消息编码成字节流。",
      "`write()`用于发送小数据包，`flush()`用于发送大数据包。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "`write()`方法本身并不会立即将数据发送出去，而是将其添加到一个内部的发送队列（或缓冲区）中。`flush()`方法则会触发一个操作，将这个队列中所有待发送的数据真正地写入到网络通道，发送给对端。这种分离的设计允许开发者进行性能优化，例如多次调用`write()`后，再调用一次`flush()`来实现批量发送。",
    "source": "文档中「netty发送的基本流程」的「4. 调用 write 方法」和「5. Flush 消息」部分",
    "hint": "文档中描述了这两个步骤的先后顺序和作用：一个动作是将消息添加到队列，另一个动作才是将队列中的消息实际发送出去。"
  },
  {
    "question": "根据文档，与异步发送相比，Netty中的同步发送最主要的缺点是什么？",
    "options": [
      "代码逻辑过于复杂，难以进行错误处理。",
      "无法确保消息被成功发送到对端。",
      "它会阻塞调用线程，在高并发场景下可能成为性能瓶颈。",
      "会消耗大量的CPU和内存资源。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "同步发送的核心特点是调用线程会被阻塞，直到发送操作完成。这意味着在高负载或高并发的环境下，大量的线程可能会因为等待I/O操作而处于空闲等待状态，无法处理其他任务，从而严重影响系统的整体吞吐量和响应能力，形成性能瓶颈。",
    "source": "文档中「同步发送（Synchronous Send）」的「4. 同步发送的缺点」部分",
    "hint": "思考一下“同步”这个词在编程中通常对线程执行流程意味着什么，尤其是在进行网络IO操作时。"
  },
  {
    "question": "在Netty中实现异步发送时，通常使用哪种机制来处理消息发送成功或失败的后续逻辑？",
    "options": [
      "通过捕获`channel.writeAndFlush()`方法抛出的运行时异常。",
      "在调用发送方法后，立即轮询检查`ChannelFuture`的`isSuccess()`状态。",
      "向`writeAndFlush()`返回的`ChannelFuture`对象添加一个`ChannelFutureListener`回调监听器。",
      "调用`ChannelFuture`的`sync()`方法来等待结果返回。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "异步发送的精髓在于“非阻塞”和“回调”。当调用`writeAndFlush()`时，操作会立即返回一个`ChannelFuture`对象，而不会阻塞当前线程。开发者可以通过`addListener()`方法为这个`Future`注册一个`ChannelFutureListener`。当发送操作完成时（无论成功或失败），Netty的I/O线程会自动调用监听器中的`operationComplete`方法，从而触发后续处理逻辑。",
    "source": "文档中「异步发送（Asynchronous Send）」的「2. 异步发送的实现方式」部分",
    "hint": "异步操作的结果通常不是立即返回的，而是通过一种“通知”或“回调”机制来处理。"
  },
  {
    "question": "根据文档描述，哪种业务场景最适合使用“单向发送（One-way Send）”模式？",
    "options": [
      "银行转账系统，必须确保每笔交易指令都成功送达。",
      "分布式数据同步服务，要求两端节点数据必须保持强一致性。",
      "大规模日志采集系统，对偶尔丢失单条日志不敏感，但要求极高的写入吞吐量。",
      "用户注册流程，需要立即告知用户注册成功与否。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "单向发送是一种“即发即忘”的模式，它不关心消息是否成功到达，也没有任何确认机制。这种模式的优点是性能极高、延迟低。因此，它非常适合那些可以容忍少量数据丢失，但对系统吞吐量要求非常高的场景，例如日志收集、监控数据上报等。",
    "source": "文档中「单向发送（One-way Send）」的「5. 使用场景」部分",
    "hint": "单向发送最大的特点是牺牲了可靠性来换取极致的性能，思考哪个选项对可靠性的要求最低。"
  },
  {
    "question": "批量发送（Batch Send）模式能够提升系统性能，其主要原理是什么？",
    "options": [
      "通过压缩多个消息来减小单次传输的数据量。",
      "将多个消息打包成一个批次发送，减少了网络I/O调用的次数和协议开销。",
      "它强制所有消息都通过同一个TCP连接发送，避免了建立新连接的开销。",
      "它能保证批次内所有消息的原子性，要么全部成功，要么全部失败。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "批量发送的核心优势在于效率优化。相比于每条消息都单独进行一次网络写操作，批量发送将多条消息在应用层或驱动层缓存起来，然后通过一次系统调用（如`flush()`）将它们统一发送出去。这大大减少了网络往返（RTT）和内核态/用户态切换的次数，从而降低了网络开销和CPU负载，显著提高了系统的整体吞吐量。",
    "source": "文档中「批量发送（Batch Send）」的「3. 批量发送的优点」部分",
    "hint": "思考一下，进行100次单独的网络请求和进行1次包含100个项目的网络请求，哪种方式的总体开销更小？"
  },
  {
    "question": "如果你正在开发一个需要确保消息可靠送达的应用（例如重要的系统警报），并且需要在发送后得到明确的成功或失败反馈，你应该选择哪种发送模式？",
    "options": [
      "单向发送（One-way Send）",
      "带有确认的发送（Reliable Send）",
      "异步发送，但不添加任何回调监听器",
      "仅调用`write()`方法，不调用`flush()`"
    ],
    "correctAnswerIndex": 1,
    "explanation": "“带有确认的发送”模式是专为需要高可靠性的场景设计的。它通过`ChannelFuture`和其监听器机制，确保发送方能够明确地知道消息发送操作的结果是成功还是失败。这使得应用层可以根据结果进行相应的处理，如失败重试、记录日志或向用户发出警报，从而保证了消息传输的可靠性。",
    "source": "文档中「带有确认的发送（Reliable Send）」的「1. 带有确认的发送定义」和「5. 使用场景」部分",
    "hint": "问题的关键词是“确保可靠送达”和“明确的成功或失败反馈”，哪种发送模式的名称最符合这个要求？"
  }
];
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            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
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            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

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                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
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                '<div class="score-card">' +
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                '<div class="score-card">' +
                '<h3>错误率</h3>' +
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                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  